Saving the integrated file system using multiple devices for a single save operation
A traditional save to a single device produces one tape file on the tape media. You can perform a save operation while using more than one media devices simultaneously.
Integrated file system data saved by a single SAV command using multiple
devices will be in a parallel save format. The data is spread across
the media devices. If you use Backup, Recovery, and Media Services (BRMS),
the save format is also parallel.
Note: Using a media definition to save your
integrated file system data to a single device specified in a *MEDDFN is
the same as specifying that device on the SAV command. It is not beneficial
to use a *MEDDFN when saving to a single device. The data is saved in serial
format.
Save scenario | Using SAV command | Using BRMS |
---|---|---|
Save integrated file systems to multiple devices | Parallel | Parallel |
This table shows the correlation between the integrated file system being saved and the name of the media files being produced.
Data saved | Number of devices | Format | Tape media files produced |
---|---|---|---|
Integrated file system data | 1 | Serial | SAVdatetime |
Integrated file system data | 2 | Parallel | Device 1: SAVdatetime Device 2: SAVdatetime |
Once you create a media definition, a convenient way to save the entire integrated file system to multiple devices is to specify SAV DEV (’/QSYS.LIB/Y.LIB/X.meddfn’) OBJ ((’/*’) (’/QSYS.LIB’ *OMIT) (’/QDLS’ *OMIT).
BRMS provides an easy-to-use interface that allows you to perform parallel save operations without creating a media definition. You specify which tape devices to use in parallel, and BRMS builds and manages the media definition for you.
- Note: Performing a parallel save with large objects might improve performance. However, if saving small objects, the performance might decrease.
- Note: Restoring individual objects from a parallel save might take a substantial amount of time.